Dados como centro de anclaje topológico en una muestra superconductora

Solving the Ginzburg-Landau equations, we analyzed the vortex matter in a superconducting square with a Dimer structure of circular pinning centers generated by a pulsed heat source in the presence of an applied magnetic field. We numerically solved the Ginzburg-Landau equations in order to describe the effect of the temperature of the circular defects on the Abrikosov state of the sample. The pulsed laser produced a variation of the temperature in each defect. It is shown that an anomalous vortex-anti-vortex state (A-aV) appears spontaneously at higher magnetic fields. This could be due to the breaking of the symmetry of the sample by the inclusion of the thermal defects.Resolviendo las ecuaciones de Ginzburg-Landau, analizamos el estado de vórtice en un cuadrado superconductor con centros de anclaje circulares en forma de una estructura de Dados, generados por una fuente de calor pulsada y en presencia de un campo magnético aplicado. Resolvimos numéricamente las ecuaciones Ginzburg-Landau para describir el efecto de la temperatura de los defectos sobre el estado Abrikosov de la muestra. El láser pulsado produce una variación de la temperatura en cada defecto. Se muestra que un estado anómalo vórtice-anti-vórtice (A-aV), aparece espontáneamente hacia campos magnéticos altos. Esto podría deberse a la ruptura de la simetría de la muestra por la inclusión de los defectos térmicos

Application of the Klein-Gordon and Bogoliubov-deGennes theories to Nickelates

In the present work we show the generalities of the classical field theory (CFT), we study its extension to the quantum field theory (QFT), where as an example of numerical analysis and combination with the field theory technique, we solve a system Klein-Gordon type (KGS) in two space-time dimensions (1+1) studying its stability through the spectral parameter λ(k), principle of convergence due to the parameters of the numerical network and the solution for the field ф (x;t), obtaining novel results. Also, we briefly study the technique of creation and destruction ladder operators from the perspective of the quantum harmonic oscillator, to define some properties and extensions to the problem in canonical quantization. Finally, we apply the topics studied to a problem of unconventional superconductivity in Nickelates compounds by solving the system of Bogoliubov-deGennes (BdG) Equations in the mean expansion of the field, obtaining the superconducting energy band

Obtención de muestras de óxidos a bajo costo

The samples obtained are nanopaticules of Iron oxide, copper oxide and Titanium nanotubes. The first two were obtained by the Sol-Gel, polymeric precursors and the third sample by the chemical anodization method. The samples were characterized by optical methods such as Raman, X-rays and scanning electron microscopy. The methods used to obtain the samples are chemical methods from which excellent samples can be obtained at a low cost and with the use of simple laboratories, especially in Colombia where the investment in research laboratories is low so far.En este trabajo se presenta un estudio comparativo de tres métodos en la obtención de muestras a bajo costo. Las muestras obtenidas son nanopaticulas de óxido de Hierro, óxido de Cobre y nanotubos de Titanio. Las dos primeras fueron obtenidas por el método Sol-Gel, precursores poliméricos y la tercera muestra por el método de anodización química. Las muestras fueron caracterizadas por métodos ópticos como Raman, Rayos X y microscopía electrónica de barrido. Los métodos usados para la obtención de las muestras son métodos químicos de los cuales se pueden obtener excelentes muestras a un costo bajo y con el uso de laboratórios simples, sobre todo en Colombia donde las inversiones en laboratorios de investigación es baja hasta el momento

Optimización de ecuaciones con restricciones no lineales: comparativo entre técnicas heurística y convexa

In this article, different optimization techniques were explored through different methodologies. It is important to highlight that optimization problems are found in a large number of academic disciplines and the paths proposed to solve them are found first in the so-called strong mathematical techniques (global optimum) through existence and uniqueness theorems, and the second way, the so-called heuristic or metaheuristic techniques, inspired mostly by biological, social, and cultural processes which allow expanding the search spaces for solutions or relaxing the functions to be optimized from continuous to non-continuous as well as constraints. The metaheuristic technique studied is the particle swarm optimization, (PSO) based on the complete model (cognitive and social components) which is a metaheuristic technique inspired by biology, comparatively with the convex mathematical technique using the behavior of positive semi-definite matrices, for the formulation and modeling of problems with objective functions and convex feasible regions. The problem solved by these two methods consists of knowing the values of the resources of two variables within an objective function. Finally, the answers obtained are evaluated under the assumption that the local minima are global minima within the neighborhood.En el presente artículo se exploran diversas técnicas de optimización a través de metodologías diferentes; es importante resaltar que los problemas de optimización se encuentran en una gran multitud de disciplinas académicas, y los caminos propuestos para resolverlos se encuentran, el primero, en las técnicas matemáticas denominadas fuertes (óptimo global) a través de teoremas de existencia y unicidad, y el segundo camino, en las denominadas técnicas heurísticas o metaheurísticas inspiradas en su mayoría en procesos biológicos, sociales, culturales, las cuales permiten ampliar los espacios de búsqueda de las soluciones o relajar las funciones por optimizar de continuas a no continuas, al igual que las restricciones. La técnica metaheurística estudiada es el enjambre de partículas, (PSO) basada en el modelo completo (componentes cognitiva y social), el cual es una técnica metaheurística inspirada en la biología, comparativamente con la técnica matemática convexa utilizando el comportamiento de las matrices semidefinidas positivas, para el planteamiento y modelado de problemas con funciones objetivo y regiones factibles convexas. El problema resuelto por estos dos métodos consiste en conocer los valores de los recursos de dos variables dentro de una función objetivo. Por último, se evalúan las respuestas obtenidas bajo la suposición de que los mínimos locales son mínimos globales dentro de la vecindad

Copper and iron oxide films deposited in Titanium Nanotubes

A tubular TiO2 / Ti matrix obtained by the electrochemical anodization method was used as a substrate for the deposit of a single litter of CuO (copper oxide) or CuO doped with 1% Fe by the spin coating method. In the anodizing methods two different times of 40 and 60 minutes were used respectively. In obtaining the anatase structure of TiO2, the samples obtained by anodization were calcined at 450 ° C and subsequently the copper oxide layer was deposited. In this study the structural properties were investigated by means of morphological x-rays by SEM measurements and optical properties through UV-Vis, Auger and Raman spectroscopy. In the X-ray measurements, the anatase phase is observed with secondary phases corresponding to the CuO. In SEM the uniform coating is observed for the method sample 2 to 60 minutes with CuO / Fe. In the measurements of Raman spectroscopy after calcination of the samples, the vibrational modes of TiO2 are obtained. In the Auger measurements, they indicated the presence of titanium in the Auger (L2M2,3M2,3) and (L2M2,3M4,5) transitions, located at 387eV and 418eV as well as Fe, O, C. Finally, our results suggest that TiO2 support -nanotubes / Ti with a CuO tank is promising for possible applications such as electrode.Una matriz tubular de TiO2/Ti obtenida por el método de anodización electroquímica fue usada como sustrato para el depósito de una única camada de CuO (oxido de cobre) o CuO dopado con Fe al 1% por el método de spin coating. En los métodos de anodizado se usaron dos tiempos diferentes de 40 y 60 minutos respectivamente. En la obtención de la estructura anatasa del TiO2 las muestras obtenidas por anodización se calcinaron a 450°C y posteriormente se depositó la camada de óxido de cobre. En este estudio se investigó las propiedades estructurales por medio de rayos x morfológicas por medidas MEB y propiedades ópticas a través de las medidas UV-Vis, espectroscopía Auger y Raman. En las medidas de Rayos x se observa la fase anatasa con fases secundarias correspondientes al CuO. En MEB el recubrimiento uniforme se observa para la muestra del método 2 a 60 minutos con CuO/Fe. En las medidas de espectroscopia Raman después de la calcinación de las muestras se obtienen los modos vibracionales del TiO2 . Las medidas Auger indicaron la presencia de titanio en las transiciones Auger (L2M2,3M2,3) y (L2M2,3M4,5) localizadas en 387eV y 418eV así como Fe, O, C. Finalmente nuestros resultados sugieren que el soporte TiO2nanotubos/Ti con un depósito de CuO es prometedor para posibles aplicaciones como electrodo

Analytical development of Ginzburg-Landau equations for superconducting thin film in presence of currents

An analytical analysis to obtain the time dependent Ginzburg- Landau equations in presence of a current J and magnetic field H in a mesoscopic superconducting thin film is shown. The transport current is applied in a little contact in the boundary of the sample. This contacts are included through to the deGennes extrapolation parameter b in the boundary conditions. Finally, we show a useful tool that can be used to found the evolution of ψ(A,t) in this formalism. We found the dependence of the magnetization M(H) and magnetic susceptibility χ m (H) with b for such sample.Un análisis analítico para obtener las ecuaciones Ginzburg-Landau dependientes del tiempo en presencia de una corriente J y de campo magnético H, en una película delgada superconductora mesoscópica, es mostrado. La corriente de transporte es aplicada en un pequeño contacto ubicado en la frontera de la muestra. Estos contactos son incluídos a través del parámetro de extrapolación de deGennes b en las condiciones de contorno. Finalmente, mostramos una útil herramienta que puede ser usada para encontrar la evolución de ψ(A,t) en dicho formalismo. Encontramos la dependencia de la magnetización M(H) y de la susceptibilidad magnética χ m (H) con b para dicha muestra

Axicabtagene ciloleucel compared to tisagenlecleucel for the treatment of aggressive B-cell lymphoma

Axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) are CD19-targeted chimeric antigen receptor (CAR) T cells approved for relapsed/refractory (R/R) large B-cell lymphoma (LBCL). We performed a retrospective study to evaluate safety and efficacy of axi-cel and tisa-cel outside the setting of a clinical trial. Data from consecutive patients with R/R LBCL who underwent apheresis for axi-cel or tisa-cel were retrospectively collected from 12 Spanish centers. A total of 307 patients underwent apheresis for axi-cel (n=152) and tisa-cel (n=155) from November 2018 to August 2021, of which 261 (85%) received a CAR T infusion (88% and 82%, respectively). Median time from apheresis to infusion was 41 days for axi-cel and 52 days for tisa-cel (P=0.006). None of the baseline characteristics were significantly different between both cohorts. Both cytokine release syndrome and neurologic events (NE) were more frequent in the axi-cel group (88% vs. 73%, P=0.003, and 42% vs. 16%, P= 2 and progressive disease before lympho-depletion. Safety and efficacy results in our real-world experience were comparable with those reported in the pivotal trials. Patients treated with axi-cel experienced more toxicity but similar non-relapse mortality compared with those re-ceiving tisa-cel. Efficacy was not significantly different between both products

Axicabtagene ciloleucel compared to tisagenlecleucel for the treatment of aggressive B-cell lymphoma

Axicabtagene ciloleucel (axi-cel) and tisagenlecleucel (tisa-cel) are CD19-targeted chimeric antigen receptor (CAR) T cells approved for relapsed/refractory (R/R) large B-cell lymphoma (LBCL). We performed a retrospective study to evaluate safety and efficacy of axi-cel and tisa-cel outside the setting of a clinical trial. Data from consecutive patients with R/R LBCL who underwent apheresis for axi-cel or tisa-cel were retrospectively collected from 12 Spanish centers. A total of 307 patients underwent apheresis for axi-cel (n=152) and tisa-cel (n=155) from November 2018 to August 2021, of which 261 (85%) received a CAR T infusion (88% and 82%, respectively). Median time from apheresis to infusion was 41 days for axi-cel and 52 days for tisa-cel (P =0.006). None of the baseline characteristics were significantly different between both cohorts. Both cytokine release syndrome and neurologic events (NE) were more frequent in the axi-cel group (88% vs. 73%, P =0.003, and 42% vs. 16%, P <0.001, respectively). Infections in the first 6 months post-infusion were also more common in patients treated with axi-cel (38% vs. 25%, P =0.033). Non-relapse mortality was not significantly different between the axi-cel and tisa-cel groups (7% and 4%, respectively, P =0.298). With a median follow-up of 9.2 months, median PFS and OS were 5.9 and 3 months, and 13.9 and 11.2 months for axi-cel and tisa-cel, respectively. The 12-month PFS and OS for axi-cel and tisa-cel were 41% and 33% (P =0.195), 51% and 47% (P =0.191), respectively. Factors associated with lower OS in the multivariate analysis were increased lactate dehydrogenase, ECOG ≥2 and progressive disease before lympho-depletion. Safety and efficacy results in our real-world experience were comparable with those reported in the pivotal trials. Patients treated with axi-cel experienced more toxicity but similar non-relapse mortality compared with those receiving tisa-cel. Efficacy was not significantly different between both products